1. Field of the Invention
The present invention relates to a heat exchanger core constituted by connecting opposite ends of a header member with corresponding opposite ends of another header member, the latter header member being positioned opposite the former header member through use of reinforcement members, as well as to a method of assembling the heat exchanger core.
The present application is based on Japanese Patent Applications No. Hei. 10-355699, 10-39704, and 11-345690 which are incorporated herein by reference.
2. Description of the Related Art
A core structure constituted by connecting opposite ends of a header member with corresponding opposite ends of another header member has already been known as the core of a heat exchanger, such as a radiator.
FIG. 13 shows the structure of a heat exchanger core of this type. In the heat exchanger core, header members 1, each comprising a header tank, are spaced away from and disposed opposite each other. Between the header members 1, tubes 3 and corrugated fins 5 are alternately arranged. The ends of one of the headers member 1 are connected to the corresponding ends of the remaining header member 1 by means of reinforcement members 7.
More specifically, as shown in FIG. 14, in the heat exchanger core of conventional structure, the reinforcement member 7 comprises the reinforcing section 7b having a C-shaped cross section and the insertion sections 7a which are continuous with the reinforcing section 7b and are to be inserted into the corresponding reinforcement holes 1b. The thickness T1 of the reinforcement member 7, which is designed in terms of strength, is thinner than the thickness T2 of the tube 3. Further, the width W1 of the insertion section 7a is set to be smaller than the width W3 of the tube 3.
The ends of the respective tubes 3 are inserted into tube holes 1a formed in the header member 1, and the ends of the reinforcement member 7 are inserted into reinforcement holes 1b formed in the header member 1. In this state, the header members 1, the tubes 3, the corrugated fins 5, and the reinforcement members 7 are connected together by means of brazing conducted within a heat treatment furnace.
More specifically, in the core structure of such a heat exchanger, insertion sections 7a as the ends of the reinforcement members 7 are fitted into the reinforcement holes 1b formed in the header members 1 and are fastened on the header members 1 by means of brazing. Accordingly, the reinforcement members 7 can reinforce the base ends of the tubes 3 attached to the both sides of the core structure, thus, four corners of the core structure on a plan view which are the most weak portions in the core structure.
As shown in FIG. 15, in the core structure of such a heat exchanger, the tubes 3 and the corrugated fins 5 are arranged alternately, with the reinforcement members 7 being provided at either end in the direction of arrangement, to thereby constitute a core section 10. In this state, the header members 1 are attached to opposite ends of the core section 10.
The corrugated fins 5 and reinforcing sections 7b of the reinforcement members 7 formed by bending so as to have a C-shaped cross section are guided along a horizontal guide surface 8a formed on a base member 8. Further, opposite ends of the respective tubes 3 are guide to individual tube guides 9 provided on opposite ends of the base member 8.
Further, as shown in FIG. 14, in the structure of the heat exchanger core, the width W2 of the reinforcing section 7b is set to be equal to the width W3′ of the corrugated fin 5.
As shown in FIG. 16, in the heat exchanger core of conventional structure, the tube hole 1a and the reinforcement hole 1b, both being formed in the header member 1, differ in size from each other. In order to simultaneously form both the tube holes 1a and the reinforcement holes 1 in the header member 1, die assemblies for punching purposes corresponding to the length of the header member 1 must be prepare, thereby resulting in an increase in the number of types of die assemblies and hence adding to manufacturing costs.
Further, in the above method of assembling the heat exchanger core, the reinforcing sections 7b of the reinforcement members 7 are guided along the guide surface 8a of the base member 8 as shown in FIG. 15. It is very difficult to form the reinforcing section 7b of the reinforcement member 7 by bending with a high degree of accuracy, so machined dimensions of the reinforcement member 7 vary widely. Therefore, the center of the insertion section 7a of the reinforcement member 7 and the center of the reinforcement hole 1b are shifted from each other with respect to the widthwise direction of the header member 1, thus causing a problem of faulty insertion.